The present invention relates to a wafer drying apparatus and method for drying the surface of the wafer immersed in pure water without causing the wafer to contact oxygen when the wafer is taken out from the pure water.
Conventionally, as in a drying apparatus disclosed in Japanese Patent Publication No. 6-103686, with nitrogen gas used as a carrier, IPA (isopropyl alcohol) is supplied in the form of vapor into an upper space in a wafer treating bath which contains a wafer treated with an etching liquid and cleaned with pure water. Then, the pure water in the treating bath is drained so that the wafer is exposed in the treating bath, whereby the IPA vapor supplied to the upper space of the treating bath is replaced with water drops held to the surface of the wafer, and so that the surface of the wafer is enabled to dry without naturally oxidizing due to contact with oxygen.
With an apparatus of the above mentioned construction, however, usually an IPA vapor of an ordinary temperature, equal to the wafer temperature that is an ordinary temperature, is supplied into the treating bath for replacement, and this involves long drying time from the evaporation of the IPA of the ordinary temperature to the drying of the wafer surface, which poses an issue of poor drying efficiency.